An auto repair shop charged a customer $381 to repair a car. The bill listed $61 for parts and the remainder for labor. If the cost of labor is $40 per hour, how many hours of labor did it take to repair the car?

Answer:

$40h+61=381 > isolate to get h by itself so subtract both sides by 61 > 381-61=320 >divide to get h> 320/ 40h >h=8 > 8 hours